Researchers at the National Eye Institute, which is part of the National Institutes of Health, have created a method to 3D bioprint eye tissue that forms the outer blood-retina barrier. This tissue supports the photoreceptors in the retina and is implicated in the initiation of age-related macular degeneration.
The researchers combined different cell types, which are primarily derived from patient stem cells, in a hydrogel carrier that is suitable for bioprinting and created a tissue structure that mimics many of the features of the native tissue. The researchers hope that the technique will allow them to create an unlimited supply of eye tissue with which to study various eye diseases.
Researchers are making strides in developing more advanced in vitro tissue models to study disease. Many diseases lack relevant and useful in vitro models and in many cases experimental animals may not accurately mimic human physiology, as well as entailing ethical concerns. Therefore, there is a need to develop more advanced in vitro systems that allow us to accurately mimic human tissues and study disease.
“We know that age-related macular degeneration starts in the outer blood-retina barrier,” said Kapil Bharti, a researcher involved in the study. “However, mechanisms of age-related macular degeneration initiation and progression to advanced dry and wet stages remain poorly understood due to the lack of physiologically relevant human models.”
To address this, these researchers developed a 3D bioprinted model of the outer blood-retina barrier. In age-related macular degeneration, the retinal pigment epithelium (RPE) of this tissue breaks down, leading to photoreceptor degeneration and eventual vision impairment.
To create the printed constructs, the researchers combined three cell types, which had been derived from patient stem cells. These were pericytes, endothelial cells, and fibroblasts. They mixed the cells with a temperature sensitive hydrogel and then bioprinted the mixture onto a biodegradable scaffold.
The researchers cultured the tissue constructs and observed that they reached maturity about six weeks later, demonstrating features of the native outer blood-retina barrier. They were then able to model age-related macular degeneration by exposing the tissue to low oxygen and they tested the effects of drugs that are used to treat the condition in humans.
“By printing cells, we’re facilitating the exchange of cellular cues that are necessary for normal outer blood-retina barrier anatomy,” said Bharti. “For example, presence of RPE cells induces gene expression changes in fibroblasts that contribute to the formation of Bruch’s membrane — something that was suggested many years ago but wasn’t proven until our model.”
Here’s an NIH video about this research:
Study in journal Nature Methods: Bioprinted 3D outer retina barrier uncovers RPE-dependent choroidal phenotype in advanced macular degeneration
lisa1 lisa2 lisa3 lisa4 lisa5 lisa6 lisa7 lisa8 lisa9 lisa10 lisa11 lisa12 lisa13 lisa14 lisa15 lisa16 lisa17 lisa18 lisa19 lisa20 lisa21 lisa22 lisa23 lisa24 lisa25 lisa26 lisa27 lisa28 lisa29 lisa30 lisa31 lisa32 lisa33 lisa34 lisa35 lisa36 lisa37 lisa38 lisa39 lisa40 lisa41 lisa42 lisa43 lisa44 lisa45 lisa46 lisa47 lisa48 lisa49 lisa50 lisa51 lisa52 lisa53 lisa54 lisa55 lisa56 lisa57 lisa58 lisa59 lisa60 lisa61 lisa62 lisa63 lisa64 lisa65 lisa66 lisa67 lisa68 lisa69 lisa70 lisa71 lisa72 lisa73 lisa74 lisa75 lisa76 lisa77 lisa78 lisa79 lisa80 lisa81 lisa82 lisa83 lisa84 lisa85 lisa86 lisa87 lisa88 lisa89 lisa90 lisa91 lisa92 lisa93 lisa94 lisa95 lisa96 lisa97 lisa98 lisa99 lisa100 lisa101 lisa102 lisa103 lisa104 lisa105 lisa106 lisa107 lisa108 lisa109 lisa110 lisa111 lisa112 lisa113 lisa114 lisa115 lisa116 lisa117 lisa118 lisa119 lisa120 lisa121 lisa122 lisa123 lisa124 lisa125 lisa126 lisa127 lisa128 lisa129 lisa130 lisa131 lisa132 lisa133 lisa134 lisa135 lisa136 lisa137 lisa138 lisa139 lisa140 lisa141 lisa142 lisa143 lisa144 lisa145 lisa146 lisa147 lisa148 lisa149 lisa150 lisa151 lisa152 lisa153 lisa154 lisa155 lisa156 lisa157 lisa158 lisa159 lisa160 lisa161 lisa162 lisa163 lisa164 lisa165 lisa166 lisa167 lisa168 lisa169 lisa170 lisa171 lisa172 lisa173 lisa174 lisa175 lisa176 lisa177 lisa178 lisa179 lisa180 lisa181 lisa182 lisa183 lisa184 lisa185 lisa186 lisa187 lisa188 lisa189 lisa190 lisa191 lisa192 lisa193 lisa194 lisa195 lisa196 lisa197 lisa198 lisa199 lisa200 lisa201 lisa202 lisa203 lisa204 lisa205 lisa206 lisa207 lisa208 lisa209 lisa210